January 2018 Summaries

The challenge was issued on May 3, with fewer than half (39 percent) of those who submitted answers able to get the correct solution. The puzzle involved a python code snippet that used historical price data from a JSON file, and required finding the minimal day moving average of close prices whose absolute difference from the 5-day moving average of open prices was bigger than the fraction of square root 2. The correct answer was found using python and pandas with a brute-force loop in just a few tens of lines of code.